With the development of display technology and the progressively increased demands on portable informational media of people, the transparent display device capable of realizing images thereon and allowing the articles at the backside thereof visible have been actively studied for the past few years. Such kind of transparent display device can be applied in windshields for vehicles and glasses for dwelling houses to provide the users with required information. Therefore the applicability of such kind of transparent display device has been significantly improved.
A conventional transparent display device has a structure comprising a display panel, a system light source located at a non-display surface of the display panel, an article placement area located at a side of the system light source that is away from the display panel, two polarizers located at both sides of an external surface of the display panel; and liquid crystal molecules in the display panel are located between the two polarizers; the polarization direction of lights is changed by processing film layers on the polarizers and controlling a rotation of the liquid crystal molecules by utilizing an electric filed, so that the article in the article placement area can be observed through the display panel under the action of ambient lights. That is, both the display content on the display panel and the article in the article placement area behind the display panel are observed, which permits a transparent display effect.
The transparent display device that realizes a transparent display effect by means of an action of cooperative polarizers in the conventional technology can achieve a good transparent display effect, however, when a transparent display effect is realized, it cannot conduct a regionally transparent display but a transparent display over the entire display panel, which, to some extent, restricts widespread application of the transparent display device.